


interdisciplinary studies

by outboxed (fallencrest)



Category: X-Men (Movies), X-Men: First Class (2011) - Fandom
Genre: Alternate Universe - College/University, Alternate Universe - Still Have Powers, M/M, Mind Sex, not even remotely serious
Language: English
Status: Completed
Published: 2014-06-08
Updated: 2014-06-08
Packaged: 2018-02-03 22:41:10
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,076
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1758745
Author URL: https://archiveofourown.org/users/fallencrest/pseuds/outboxed
Summary: <blockquote class="userstuff">
              <p>When Charles Xavier signed up to be a TA at the beginning of his graduate studies, he’d expected to be assigned to help his favourite professor from undergrad, Moira MacTaggart, with <i>Biology 101</i>. Instead he finds he’s been requested by Professor Lehnsherr, a man he’s never met and who teaches a subject Charles has never studied. Charles doesn’t know why Lehnsherr picked him but, it turns out, he has his reasons.</p>
            </blockquote>





	interdisciplinary studies

**Author's Note:**

> Written in response to the prompt “Charles/Erik - University AU: Where Charles is the TA to a cranky but brilliant and very, _very_ handsome Professor Lehnsherr” at the LJ kinkmeme back in 2011.

Charles was nervous as he knocked on Professor Lehnsherr’s door. When he’d signed up to be a TA during the graduate application process he’d always imagined being assigned one of the professors who’d taught him as an undergrad. He had a good relationship with Moira and he’d hoped she’d ask him to be her TA for _Biology 101_. She was his postgrad supervisor and they got along well - it seemed an easy, logical option for both of them. In his first meeting with her that fall though, she’d turned to him and said, “I see you signed up to be a TA this year. Professor Lehnsherr requested you to help him with _Intro to Mechanical Engineering_. Did you minor in it or something? I didn’t know. Either way, he’ll probably be in touch in the next few days. If not, you should probably call by his office. It should be over in the physics department.”

Charles had been too taken aback to ask questions. He hadn’t attended a class in mechanical engineering in his life and he had no idea why he’d been requested by a professor he didn’t think he’d ever even heard of before to be his TA in a field which was so far removed from his own. He tried to think if Lehnsherr might have taken one of the few physics papers he’d done as an undergraduate and completely drew a blank. 

He checked daily in both the biology and physics graduate offices to see if Lehnsherr had left a message for him to no avail. He didn‘t send a message through any of the university’s other channels, either, so, on Friday afternoon, he decided to go to Lehnsherr’s office. He felt a little unsure about it but classes started next week and he needed to be in the loop - he didn’t want his first TA appointment to go badly and he was completely unfamiliar with the syllabus.

He knocked, with a little less force than he perhaps ought to have.

“Come in,” came the voice from inside. There was no window in the office’s wooden door so Charles opened it without any idea of what would greet him on the other side. 

It wasn’t a large office but it wasn’t cramped, either. The desk was pushed up against a large window, which amply lit the room, and books lined the walls on both sides of it. Professor Lehnsherr was sat at his desk with his back to the door and didn’t bother to turn around when Charles came in. 

“Well,” he asked, still not turning around, “what is it?”

“I, um, I’ve been assigned as your TA, for _Introduction to Mechanical Engineering_ , my name’s Charles Xavier.” It was unsettling, to address the back of the guy’s head, but Charles couldn’t see what else he could do. 

At the mention of Charles’ name though, Lehnsherr swivelled his chair around to face him, a smile spreading across his face. “Ah, Charles,” he said, getting up out of the chair and stepping towards Charles, hand outstretched.

Charles shook the proffered hand, a little taken aback. Lehnsherr was tall, young and, Charles hated himself for thinking it, but actually surprisingly handsome. 

“I didn’t actually—” Charles began, gaze nervously falling somewhere around Lehnsherr’s shoulder.

“Study mechanical engineering as an undergrad?” Lehnsherr asked, “I know. That won’t be a problem. The syllabus is rudimentary and you’ll pick it up soon enough. You’ll be sitting in on the classes anyway.”

“When are the classes?” Charles asked, feeling like an idiot, as he was reminded just how unprepared he was for this. He’d only read the TA’s guide briefly when he’d signed up for the position, he’d assumed Moira would tell him the rest. It was different asking stupid questions of a professor he already had a rapport with, one know knew that he was perfectly capable, but this was actually quite embarrassing. 

“Oh, right, Monday mornings, 10-11:30. There will be labs, too, and you’ll have to grade papers and have guidance sessions with the students but we can work that out later.” Lehnsherr raised a hand as he spoke, as though casually waving away the complexities of the whole thing. 

“Is there anything I need to do now? Or anything I need to know?” Charles asked him, thoroughly wrong-footed. It didn’t help that Lensherr was standing so damn close after their handshake. He smelt really good, Charles realised. He’d always known that good cologne could work wonders but he’d never felt its effects so strongly before. He found himself staring at collar of Lensherr’s turtleneck as he awaited the answer.

“Well, I suppose you ought to have a look over the course reading as you’re unfamiliar with it. It’s not too important though. I’ve asked the students to read chapters 1 through 3 of the textbook for our first class.”

“Right, um, what’s the textbook?” Charles fumbled his way through another five minutes or so of conversation with the professor before he left Lehnsherr’s office, an old copy of the course textbook in hand, along with a torn slip of paper. The paper has the room number on it, handwritten by Lehnsherr, after Charles had realised he didn’t know where the class was and then that he didn’t have a pen or any paper. Lensherr was relaxed, easy about the whole thing and not at all impatient with Charles - though Charles got the impression that he wasn’t one for aimless chats or doing a whole lot of hand-holding either with students or his TAs. 

The interview had ended with Lehnsherr asking whether Charles had any other questions. Charles had wanted to ask why Lehnsherr had asked for him to be his TA but he’d stopped himself, aware that Moira might be wrong about Lehnsherr having sought him out. He’d ended up saying, “No, I’ll see you on Monday then.” 

Lehnsherr had smiled the same easy, natural smile he’d smiled when he first turned to face Charles and said, “Monday,” and Charles had left, with _An Introduction to Mechanical Engineering_ clutched to his chest. His apprehension about what this TA position involved weighed more heavily on him the further he got from Lehnsherr’s office and Lehnsherr’s apparent faith in Charles’ ability to TA for a class he’d never taken, in an area which was far from his specialism. 

*

Charles spent the weekend attempting to do all the reading for his first graduate biology class whilst staring down _An Introduction to Mechanical Engineering_ , sat on the far corner of his desk. 

“What the hell are you doing with an undergrad mechanical engineering textbook?” Hank had asked him when he first spotted it.

“I’m TAing for Professor Lehnsherr’s freshmen intro class,” and it occurred to him then, for the first time, that if anyone he knew had info on Lehnsherr it would be Hank - he was in the department after all. “Do you happen to know anything about him, by the way?”

Hank had shrugged. “He’s pretty anti-social, to be honest. Never in the faculty lounge. I think he’s pretty committed to his research though. You know how it is. I’d be that way if I thought I could get away with it.”

“You get ten times the amount of work done as everyone else in half the time,” Charles said, “you have plenty of time to be sociable.”

“I guess. Anyway, I think Lehnsherr’ll probably ride you pretty hard as a TA - given that he has no time for the other staff, I doubt he’ll be one for nurturing the students.”

“I got that impression,” Charles agreed, though he’d felt a slight flush creep up his neck when Hank had so casually mentioned Lehnsherr ‘riding him hard’. _This is going to be a hell of a term,_ Charles thought, and tried to resign himself to it.

 

Monday morning dawned, as Monday mornings are wont to do, and found Charles reluctant to get up and confront a class of fresh-faced freshmen in what was likely the first class of their entire degrees. Whilst showering, he lamented the fact that he’d hadn’t gone out to the pub the previous night, despite a couple of invitations, thinking that a hangover might actually have been better than these ridiculous nerves. He didn’t normally get nervous in situations like this - he was good with people, he found it easy and he had a good few advantages over other people when it came to empathy - but it was his first time TAing a class. He’d only managed to slog through a chapter and a half of _An Introduction to Mechanical Engineering_ last night and taken in less than half of that in because he kept distracting himself with worries about what he’d say if he was asked a question about any of it or, worse, about something that wasn’t in the textbook. Additionally, there was the incredibly hot and actually-kind-of-mysterious and aloof professor to factor in. God, this would be easier if he were hung-over, he knew it would be. 

In spite of everything, he dragged himself over to the labs. When he arrived, the classroom was empty and he feared he’d gone to the wrong place. Just as he was pulling the slip of paper with Lehnsherr’s immaculate (and slightly effeminate) handwriting on out of his pocket to check that this was the right room, the professor himself entered. He was wearing a brown leather jacket and he walked up to the teacher’s desk without paying Charles’ any attention at all. He laid his briefcase on the desk and snapped it open before he looked up at Charles, offered him another of those surprisingly easy smiles, and then went back to the papers in the briefcase, sorting through them and pulling out various stacks.

The freshmen, when they arrived, were actually not at all fresh-faced after their first weekend at college. Lehnsherr had Charles hand out a stack of photocopies with the full course outline on and Charles took one for himself, just to be safe. 

The first class was primarily an introductory lecture which covered everything from ‘why study mechanical engineering’ through to a discussion of the basic texts they might want to look at for further reading. Lehnsherr was more passionate than Charles had expected from their previous meeting and the little that Hank had told him. Talking about his subject, his intonation changed and his voice took on a rapt quality. He didn’t sound as though he was addressing anyone in particular and he gave little indication that he was aware of his students’ presence. 

It wasn’t the first time that Charles had been in a class with a professor who changed when they talked about their subject or the first time that he’d had a first class taken up almost entirely by the professor lecturing - some of them did it every week - but there was something different about Lehnsherr. Charles couldn’t quite say what it was but he watched and listened as the professor spoke and found himself forgetting that he was meant to be anything other than a passive listener. Partway through, he sat down on a desk near the front of the room but he still found himself looking at Lehnsherr rather than at his - _their_ \- students. 

Charles had had crushes on teachers before. He’d even hit on Moira once - when he’d been very, very drunk and before he’d known her, thank god, but still. It wasn’t that unusual, he supposed, and Lehnsherr was a beautiful specimen, speaking as a human biologist. This was different though, partly because it felt stupidly intense at the moment and partly because he was meant to be working with the guy, working for him even, and he was probably going to have a whole lot of one-to-one meetings with him (sat opposite him, close enough to smell his cologne). 

The class ended with Lehnsherr asking if anyone had questions and a few students did. Most of the questions were about how the course was being assessed, what sort of tests they’d have and how much of the course was likely to be practical rather than theoretical. Lehnsherr answered them all and didn’t appear irritated when some of the students asked questions which were clearly outlined on the info sheet they’d been given at the start of the class.

“For next week,” he said, as he wrapped the class up, “read chapters 1 through 5 - I’m sure some of you haven’t managed 1 through 3 yet - and there are question sheets which Charles will hand you on the way out. They’re just reading comprehension, basically, but hopefully they’ll ensure that you’ve taken in the basics, at least.” 

He handed Charles another set of sheets from his orange-brown briefcase and gestured to have Charles stand in the doorway so that he could hand them to each student as they left the classroom. 

Charles took his shoulder bag with him as he headed for the door, expecting to leave after he’d handed out the sheets, but when the last student left Lehnsherr called out, “Charles, don’t go yet.” Charles stood awkwardly in the doorway for a moment whilst Lehnsherr packed his things carefully back into the briefcase. He wasn’t sure what Lehnsherr wanted but he was hoping that Lehnsherr was going to give him a clearer idea of his duties. 

“We should talk,” Lehnsherr said, as he approached Charles, “about the course and about the whole TA thing. My office, via the coffee lounge?”

“Sure,” Charles replied. Lehnsherr was up next to him now and he could smell his cologne again, subtle but pronounced, as he stepped out ahead of him through the door.

*

“So,” Lehnsherr said, as they headed to physics department’s faculty coffee lounge, “I guess I’ve not been entirely candid with you.” He paused, looking at Charles, who had no idea where this conversation was going. “I didn’t pick you as my TA because I misread your transcript and thought you were a physics major. That’s probably obvious.” If he wasn’t very much mistaken, Charles thought there was a kind of nervous hesitance to Lehnsherr’s speech. “I asked for you as my TA because your research proposal interested me, really interested me.” Lehnsherr was looking at him, in a way which read ‘really interested’ in ways Charles would really want to explore - if he were drunk and Lensherr wasn’t the professor in charge of the class he was TAing for. “I’m an engineer, yes, but genetics have always fascinated me and your thesis, there’s, um, something I want to show you when we get back to my office.”

Lehnsherr pushed open the door to the coffee lounge and held it for Charles whose brain was wildly contemplating what Lehnsherr might want to show him, occasionally going places it really ought not to have given that it was 11:30 in the morning and he was stone-cold sober. 

The faculty lounge was silent and a few members of staff were sat reading in the lounge armchairs. Hank was in one corner, mug in hand, and a stack of papers on a low table in front of him but Charles didn’t see him look up. He watched Lehnsherr work the coffee machine with his long fingers, trying not to let his brain go where the image wanted to take him. If the room hadn’t been so silent, he might have said something to distract from the thought, but the pervading silence and the fact that he was only a graduate student, and not even in the physics department, stopped him in his tracks. 

“Do you take sugar?” Lehnsherr asked, in little more than a whisper, head bowed and close to Charles’, as he stirred his own coffee. “Milk?”

“Milk, no sugar.” Charles said back, in what was probably actually a whisper. He hoped he wasn’t blushing.

On the way out, Charles held the door, aware that Lehnsherr had his hands full with his briefcase and his coffee. 

“Sorry,” Lehnsherr said, after the door had closed behind them, “you must think I’m a bit weird right now. It’ll all make sense soon though, I hope. Have you ever,” Lehnsherr paused, that uncharacteristic nervousness he’d shown earlier returning, “thought about the practical applications of your thesis? I mean, well, not practical but—” he took a breath, “about the ramifications of your thesis in relation to human mutations in contemporary society.”

“It was my starting point,” Charles admitted, feeling, curiously, more confident as the professor appeared less certain. “I suppose it started as a personal interest.”

“Family history of genetic disease or—?”

“Not quite — but I suppose you could call it that. It’s stupidly complicated, really, but the answer to your first question is yes.”

“Good,” Lehnsherr said, seeming a little distracted, “good.” 

They climbed the stairs to his office in silence and, looking around the corridor once they reached his door, Lehnsherr paused before reaching for the door handle. 

Inside the office, Charles noticed for the first time that there were a few chairs at the sides of the room, in addition to Lehnsherr’s desk chair. 

“Sit down,” Lehnsherr said, gesturing to one of them and sitting down himself. “I hope you don’t mind if I cut the crap and just show you why I brought you here.” He set his coffee down on the corner of his desk and picked up an oversized paperclip from his desk, holding it out on the palm of his hand. Charles watched, frowning, as the professor continued, “there’s something I can do, something few people would believe but I thought, I don’t know, when I read your research proposal, something told me—”

The paperclip was floating a few inches above Lehnsherr’s hand. Lehnsherr was watching Charles stare at it. The paperclip crushed itself in mid-air, stretched itself out and then re-formed itself into an ordinary paperclip again, without anyone ever appearing to touch it. 

“You,” Charles said, taken aback, “have always been able to do this?”

“Not always.” Lensherr said, curtly, “But since I was quite young.” He frowned as he looked at Charles. “You aren’t as surprised as most people would be but, then, I thought you might not be.”

“Did you know?” Charles asked, swallowing, “About me?”

“Did I know what about you, Charles?” Lehnsherr asked, leaning forward in his seat, his hand closed around the paperclip now. Lehnsherr’s eyes had an intense edge to them and they were remarkably blue and remarkably close, Charles thought, before schooling his mind to do what he knew he had to.

 _That I can do this,_ Charles projected, and Lehnsherr’s eyes widened as he sat up straight again. _I can read your mind, too, but I don’t - causes too many problems._

Charles began to smile as he observed Lehnsherr’s expression. It was rapt and taken aback, awed but not disgusted or reluctant. 

“I had a feeling about you, Charles.”

“Well, I’m glad it was a correct one, Professor, or this might have been a very different conversation.” Lehnsherr’s awe buoyed Charles up, made him feel the way he normally felt - less like a foolish boy, more like a man who knew what he wanted and how to get it.

“You can call me Erik,” Lehnsherr said, smiling at Charles. “I’m very glad to have met you. I hope you don’t mind that you’ll be grading my papers all term but, hopefully, it’ll mean we’ll be able to spend a deal of time together.”

“I don’t think I’ll mind,” Charles replied, smiling back. He’d not revealed his gift to anyone since Raven and they’d become a little estranged since he’d utterly failed to keep to their agreement about mind-reading.

They talked practicalities for the rest of the meeting. Erik gave him some advice on grading papers and Charles let Erik know when he would be busy with his commitments as a graduate student. At one point, Erik had opened a drawer with his power, his whatever-it-was, and a stapled set of photocopies had lifted themselves out and made their way into Charles’ hands, a display which made him grin like a fool. 

“Do you think there are more of us?” Erik asked, shortly before Charles left his office, almost an hour later.

“I’m sure there are.” Charles said, emphatically. 

*

“What are you grinning about?” Hank asked him, the next Monday evening, whilst Charles attempted to make an early start on grading Erik’s reading comprehension questions. 

Charles wasn’t sure how to answer: ‘Erik-fucking-Lehnsherr’ did not seem like a good choice so he thought about it a little more. Maybe the cause of the irrepressible grin was the fact that, during class, Erik had set the students some tedious task and then turned to Charles, looked intently into his eyes, raised an eyebrow, and then thought _test, test, come in Charles Xavier, do you read?_

Charles found it hard not to laugh and felt relieved that he’d interpreted the look Erik had given him correctly, as an invitation to read his mind. _You don’t have to look at me for it to work, you know,_ Charles told him, silently, looking in the direction of the students to prove his point.

_But I needed you to know that I was okay with it - since you said you don’t normally read people’s minds. I hope you haven’t been reading mine all along, I‘d hate to think what you would have found out._

_God, no, I’d never—_ Charles told him, looking back at Erik and seeing that he was smiling. 

_Still, I bet you could listen in on everyone in the room and see if they’re actually thinking about mechanical engineering,_ Eric thought, mischievous look still on his face. 

_You could listen to them with your ears and find out that they weren’t,_ Charles projected, returning the smile. 

_Still, nothing’s a secret from you, is it?_

_Like I said last week, I normally try not to do this. It can make things awkward._

Erik raised an eyebrow again, thought _like this_ and then a some things which weren’t words and watched a blush spread across Charles’ face. 

“Right, I think you’ve had enough time to discuss.” Erik said, addressing the room now, “I’d like feedback from each group, starting at the front of the room,” he gestured to a group near the front of the class, “what did you all discuss?”

At the end of class, Erik told the students to address any questions they had about last week’s question set to Charles, as he’d marked them, and then left, smiling over his shoulder at Charles as he left the room before him. Charles found himself unable to follow Erik out as one of his students approached him, anxious to know how she’d dropped a point on this or that question when she were sure that her answer was copied, verbatim, from the textbook. 

 

Every night that week, Charles dreamt of the things Erik had shown him at the end of their silent conversation: semi-pornographic images of fingers on skin, Charles’ flushed face, his neck arched. He thought about how Erik had just invited inside his head like that and how it had felt, reaching out inside someone’s mind and finding himself welcome there.

In his meeting with Moira, she asked how he was getting on with Professor Lehnsherr. He replied, “Yeah, great, Erik’s really nice,” and he could swear his ears were burning but she went on as normal, asking how he was finding teaching a subject he was less familiar with. He’d told her that it was fine, a challenge but nothing that he couldn’t deal with. He also told her that he’d made considerable advances in his research but resisted the urge to tell her about Erik - it wasn’t his secret to tell, supportive though Moira had been when he’d explained to her that his interest in genetic mutation wasn’t solely academic. 

*

Friday afternoon found Charles attempting to read the new month’s edition of _American Journal of Human Genetics_ in the library reading room. He’d already disregarded some of the articles which sounded wildly irrelevant to his area of interest but, even with an article which seemed plausibly relevant in front of him, he couldn’t prevent his mind from wandering. _Erik-fucking-Lehnsherr_ , he thought, as his mind slid to the thought of long fingers digging into his skin and a voice resonating silently in his mind. _God, Erik, you have no idea what you’re doing to me,_ he thought, picturing Erik in his mind, unsure whether or not that in itself would be sufficient to make Erik hear Charles’ thoughts in his own mind.

 _What am I doing to you, exactly, Charles?_ The tone of the query was light, amused, and saturated with Erik’s voice and the feel of him, thrumming through Charles’ mind. Charles didn’t know how to answer it, didn’t know how to say that just those few fleeting images, the things Erik apparently wanted to do to him, were keeping him up at night and keeping him from functioning like a normal human being. _Charles?_ Erik’s familiar voice repeated the enquiry.

 _Last night, I went out and got shit-faced and unsuccessfully hit on three girls and had to have a friend bundle me into a cab all because I can’t sleep at night for thinking about those_ things _you showed me._ Charles slammed the journal in front of him shut - if it hadn’t been a hopeless cause when he’d started out, it was now. _God, this is really inappropriate. We should pretend this never happened._

_We should really not pretend that this never happened. You’re the only person I’ve ever met who’s like me and you’re— Charles, you can read my mind: you tell me what I think about you._

Charles’ breath caught at the very idea of letting himself see what Erik thought of him but, even as he told himself not to, he started to see. 

_How far away are you, exactly?_ Erik’s voice said, clear above the tumult of his thoughts. 

_The library,_ Charles thought, _the library,_ his mind too caught up in Erik’s - in the images Erik was projecting - to form coherent sentences.  
 _  
Where do you live? Is it far? I— I think we should._

_I know exactly what you’re thinking._

_I know. So, far?_

_Not far. Fuck, I can’t— I really, really can’t. This is so—_ Charles found himself stumbling to a bathroom stall in the library and palming his cock through his jeans before taking it out. _God, Erik,_ he gasped, and he said it aloud as well as in his head and Erik was there all the time, just as he was with Erik. _This— Fuck._

 _I know._ The words were clear in between everything else he could feel in Erik’s head, edged with desire. _Can we— in person?_ Erik asked, _I mean—_

 _Yes,_ Charles gasped and he thought he managed to keep the words silent this time. _Yes. Definitely yes._

*

Evening found them both in Erik’s bed. Charles had met him in the parking lot outside of the physics department, as soon as he’d felt confident in his ability to appear in public again without attracting stares. They’d made a pact of psychic silence whilst Charles attempted to pull himself together in the bathroom stall and agreed to meet by Erik’s car and go back to his apartment. 

When Charles approached Erik, he was pleased to see that he, too, was looking a little fucked out and unpresentable. 

“You know,” Charles said, as he climbed into the passenger seat, “I haven’t wanked off in a public toilet since I was 15 at least.” 

“You say that as though you used to do it all the time.”

“Maybe I did.” Charles was looking at Erik and grinning as passenger door slammed shut without anyone touching it. 

It was quite possibly the most torturous ten minute drive Charles had ever been on. “How far away do you live? I mean, I know we avoid the roommate problem this way but…” 

“This is my street,” Erik promised, as they rounded a corner, and soon they were parked and Erik was leading the way up the steps to his apartment. 

“Want to see something cool?” Erik asked.

“I actually kind of just want to—” Charles began, as the lock clicked open by itself and the door swung wide. One of Erik’s hands grabbed onto his belt and tugged Charles inside as Charles stared at the lock. 

_That was awesome. You’re awesome. Now close it so we can fuck._

Charles’ smile was infectious and Erik replied in kind and thought: _deal._

 

“I suppose,” Charles said, lazily, the next morning as they ate toast at the counter in Erik’s kitchen, “that you want me to introduce you to my other mutant friends?” He took a bite of toast and then frowned, “but I think that if I did you might decide you wanted to sleep with them instead and I would not be in favour of that.”

Erik met his eyes across the counter and thought, _why would I want to sleep with them when I have you? Read my mind, if you don’t believe me._

 _I believe you,_ Charles thought back and then: _but, God, I don’t know how I’ll get through class on Monday if you keep making me feel like this._

“Come on,” Erik said aloud, “Let’s—” and Charles saw what he was thinking and couldn’t help but agree. 

*

Monday’s class was close to unbearable. They’d made another pact of psychic silence but Charles could tell from Erik’s eyes what he was thinking when he looked at him. Charles tried to make the time go faster by moving between the groups of students as they worked on the task Erik had set them, asking them if they needed any help. Surprisingly, he found himself able to answer most of their questions or to give reassuring prompts so that the students would examine their own thought processes and find the answer for themselves. He could see Erik’s sultry, jealous look when a girl in a skimpy vest smiled at him. He’d grinned, looking first at Erik then back at the girl and told her to keep up the good work before he moved on to the next group.

On Wednesday, he met with Moira. He had the most outrageous hickey and no shirt with a high enough collar to cover it. Erik had made a joke about how Charles could borrow one of his turtlenecks but Charles had turned him down, fearing that it really was just a joke and feeling sure that someone would spot that it was Erik’s and make even stronger conclusions on that basis than they might otherwise have done. Instead, he’d decided to wear his thick winter scarf, hoping that it would do the job but he knew from the looks he’d been getting all day that it never stayed in place for long. Moira had given him a wry smile when she spotted it and asked him how he was enjoying graduate study.

“It’s great,” he admitted and continued, knowingly, “the extracurricular activities are fantastic and my research is really coming along.”

“Oh, really?” she said, half-sarcastic, “what exactly have you been researching?”

“Well, I’ve been looking into magnetic fields, actually.”

“Magnetic fields?” Moira asked, intrigued and a little puzzled now, the jocularity almost entirely gone from her tone.

“Yes, you see, they’re susceptible to all kinds of interference and, whilst they’re a far cry from human biology in some respects, I’ve discovered that it’s possible for them to be affected by the human mind. At least, I think it’s the mind. I knew before this, of course, that it was possible for human mutations to allow for the manipulation of other humans, their perception, their brainwaves, but not that a human, who possessed a mutation, might manipulate other forces of nature. It really is quite fascinating.”

“You’ve met someone then?” Moira asked, her sceptical, amused expression returning. “Could this be the same someone who gave you that fabulous badge of honour?”

Charles touched the tender spot on his neck, self-consciously. “How did you know?” he asked, curious and without offence. 

“Lucky guess. I figured it would take one of your own to really get your guard down.”

Charles frowned a little, “It’s not because of his mutation,” he said, with a touch of petulance, realising, as he said it, that it probably was, in a way. He’d known before he knew, he suspected. Everything had been different with Erik, that bit more urgent and real, unlike anything he’d felt before. He wasn’t sure if that made sleeping with the professor he was TAing for more or less excusable - he doubted the university would have a policy on relationships which were doomed to happen because of what might be considered a genetic predisposition. Perhaps it was worth researching: it was surely a valid topic for wider investigation.

“Charles?” Moira had asked, when he’d fallen into this reverie. 

“Yes, sorry, just thinking about my research. Genetic predispositions. Inevitabilities.” Moira looked unconvinced and Charles didn’t protest. 

*

Learning to control themselves and establishing boundaries for their relationship is difficult and takes time. They slip up more often than they should because Charles can’t keep his mind from searching out Erik’s. It is a long time before Erik learns not to project the things he wants to do to Charles and starts not to mind suppressing those thoughts when he knows he can play them out later, for real. It takes even longer for Charles to become used to sliding into Erik’s mind and settling there, in amongst everything. Becoming a part of Erik’s mind loses its edge but it becomes, for all that, like going home. Charles comes to know it all, all the dark places and the things that Erik tries to hide, and he accepts it all because it’s all a part of Erik. 

It’s a steep learning-curve, discovering how this all works. One notable morning, their first night at Charles’ apartment, Erik tried to confess that he hadn’t told Charles everything about him. He started to say that there were things that Charles should know about his past, his work, before Charles cut him off, saying, “I know everything, Erik, everything.” 

Erik’s expression changed then and he looked lost, a little scared. Charles kissed him, soft and slow, then said, “That’s how it works, Erik, reading your mind. It’s not terribly selective once I go beyond the very superficial. I can’t help it.” He placed a hand on the back of Erik’s neck, fingers in his hair, and said, “I know everything.”

Hank had knocked on the door then, and called out, “Charles, seriously, what have you done to the apartment?” 

Charles and Erik exchanged confused looks before Charles called back, “Just a minute.”

When Charles emerged from the room, he could immediately see what Hank meant: all the cutlery in the house was strewn across the floor and, across the room, there was a deep gouge in the plaster where the butcher‘s knife had embedded itself there. Most of the kitchen cabinets had been pulled open and the metal handles of one or two appeared to have come loose. Charles began to say, “Umm,” stalling for an explanation, when Erik appeared out of the bedroom, in sweatpants, coughed, looked a little startled and then attempted to explain.

“That must have been me, I, um, I don’t have a thing for throwing cutlery or anything, and normally I’m pretty in control but…” he swallowed, “I’ll clear it up,” he said, closing his eyes, feeling for the metal with his mind and lifting all the scattered pieces up to place them in the kitchen sink. He flushes, a little, when he realises he’s put Hank’s glasses in there, too, and that the lamp is hovering ominously, not quite above the cabinet it’s meant to be on because he’d picked it up before he realised that it wasn’t want he wanted. He rectified those small things soon enough though and apologised to Hank whose glasses were now floating steadily in the air in front of him. “I’d put them on you, only, well, I don’t seem to be quite on form this morning and I really don’t think you’d like me more if I took your eye out or something by mistake.”

Charles grinned at Erik and Hank looked more amused than annoyed by it all. “Don’t worry about it,” Hank said, “we all have our little things.”

“What’s yours?” Erik asked, a little over-eager, before he could stop himself.

“Oh, it’s nothing cool, I just—”

“He’s a genius,” Charles cut in, “and he has these special feet.”

Hank looked a little abashed and Erik noticed here the same thing he’d begun to see in Charles as he’d grown in confidence as a TA. Charles, he realises, nurtures people: he sees their weaknesses and turns them into strengths and he praises everything that’s good without ever making them feel bad about what they haven’t done.

After a little reluctance, Hank showed Erik his feet and Erik seemed impressed. He told Hank how he’d never seen a mutation which manifested itself physically like this and Hank had brought up Raven and said that he thought they’d get along. Charles silently agreed with Hank but he wasn’t sure that he was quite ready to introduce them yet. 

*

Erik takes to spending a good deal of time at Charles’ apartment and Charles becomes used to the sight of him, sprawled on the sofa in the morning, reading a book about some obscure area of materials science, a pot of coffee brewing which Charles suspects Erik has set in motion with his mind rather than with his hands.

“Morning,” Erik said, looking up with a smile when Charles emerged from the shower one morning, clad in only a towel.

“Morning,” Charles replied, leaning over the back of the sofa and planting a kiss on the back of Erik’s neck. “What are you reading? That contraption looks, frankly, bizarre.”

What Erik had in front of him this morning was not his usual musty-looking, academic hardback but a set of papers which were covered in rough sketches. “Actually, I was trying to work that out myself. I found them on the coffee table. They’re, um, interesting. Not your work, I take it?”

“No, I’ve definitely never seen anything like it before. I’d guess these sketches are a plan for one of Hank’s stranger inventions.”

“Is Hank a physicist then? I mean, his calculations are— I’m a little surprised but they make _sense_.” Erik said, frowning at the diagrams as though their plausibility offended him. 

“Of course he’s a physicist, Erik, he works in your department!” Charles said, unbelieving, “I can’t believe you haven’t seen him. He was there in the coffee lounge that first day when we had our little chat. You are unbelievably single-minded, Erik. You’ve even met him, spoken to him extensively.”

Erik frowned slightly, “If that‘s true then I can see that it was an oversight on my part, not to have realised.”

“A big one.”

“But I was just too busy paying attention to you,” Erik said, taking his eyes off the papers for the first time and turning to look at Charles. Charles laughed at the ridiculous sentiment - though Erik seemed bizarrely genuine. 

“So, what are these designs for?”

“It’s a, well, a headset, I suppose, designed to boost your powers - I think so that you can find more of us, more mutants, I mean. I’m surprised Hank hasn’t spoken to you about it.”

“He did, actually, at least, he mentioned it yesterday, sort of. I mentioned that I’d be interested to find more of us and he said that maybe it was possible and then disappeared into his room and this must be the outcome.”

“Hank started designing this _yesterday_?”

“He’s a genius, Erik.”

“I suppose he is. So, are you going to use it?”

“I’m game if you are. I mean, it would be good, don’t you think? Not to be alone? I’ve searched out a few of us already but the possibilities that a device like this would open up: I think we should at least try it.”

“Agreed.” 

*

Charles doesn’t know how he makes it through the rest of _Introduction to Mechanical Engineering_ that term but he does make it through. The work is only undergraduate level, after all, and it doesn’t take too much effort to pick up everything he needs to know. If he has questions whilst he’s grading he asks Hank, consults the textbook again or the checks against the answers of one of the better students and, whenever he’s asked a particularly pointed question in a meeting with a student, he has a direct line to Erik he can use.

He’d once ended up with a student asking about applying some principle he’d never heard of to the construction of lightweight engines and he’d put two fingers to his temple, as if in thought, and asked Erik.

 _The simple, undergrad level answer is that it’s possible but not worth calculating. It’d take weeks. If they have any more specific questions, just ask._ Erik’s answering tone was measured, kind and friendly but it changed when Charles had asked if he couldn’t just direct the students to him, when they have stupidly complicated questions like this. _I have a book to write here, isn’t dealing with students what I have you for?_

 _It’s definitely not what you have me for,_ Charles had replied, with a grin he feared might be slightly filthy, as he pretended to come out of a thoughtful reverie on the student’s question and relayed Erik’s answer to the student as though he’d just come up with it himself. 

Their whole arrangement was working out pretty well, all in all, and their plans for the Christmas vacation were only getting more interesting as Charles began to locate other mutants using the device Hank had made from his prototype sketches. He’d called it Cerebro and Erik had laughed when Charles first used it. He distinctly remembered talk of lab rats but Erik had fallen quiet soon enough, when Hank had flipped the switch and all co-ordinates began to type themselves out. 

“That was amazing.” Erik had said afterwards.

“There were so many,” Charles replied, raptly, “So many of us, Erik.”

*

In spite of the self-control they’d marshalled all semester, Erik disregarded all their rules during Charles’ last job as his TA.

It was the final Friday of the semester and Charles was meeting with students to hand back their assignments. When he was done they were due to set off on a road-trip to try and find the mutants that Charles’ first uses of Cerebro had located. 

It had begun innocently enough with Erik alerting Charles to his presence by moving his change across the table. Charles had set himself up in a campus coffee bar and his first student was due any minute. _Where are you, Erik?_ He asked, when he realised all of his change appeared to be making a break for the floor, each coin moving in a distinct direction, some rolling, some sliding toward the edges of the table. 

_I’m in my car, in the lot behind you, and I can see the back of your neck, your hair - which still hasn’t really recovered from this morning - and, oh look, there’s one of the kids from Intro walking right up to you. Enjoy._

Charles had wanted to turn around, to see that Erik was really there, or at least to come up with a retort but Erik had been right about the student and Charles only just managed to school his face into a welcoming smile when the student drew out a chair opposite him. 

“Hi George, so I’ve marked your assignment and it was really good. Just bear with me for a minute while I dig it out of the pile. How did you feel it went?”

Handing back that first assignment had been fairly straight-forward and Charles felt that he was doing a pretty good job, all in all. It wasn’t until his ninth student was running late for her meeting with him that things started to get bad. Erik was obviously fed up of waiting and, when Charles looked over his shoulder to see Erik leaning against the hood of his car, smoking and looking in at him, he couldn’t help but reach out and say, _don’t worry, only three more to go and then we can leave._

_Oh the things I’m going to do to you when we leave. Think of the hotel rooms, Charles. Can’t we just go now?_

_Erik, you know we can’t._

_But I just want to push you up against a wall and—_ Charles closed his eyes for a second, seeing it all too clearly. _I even just want to go to a restaurant with you in some faraway town and lean across the table and kiss you and not care who sees._

Charles sorted through his papers again, the stack of assignments somewhat depleted now. _You know,_ Erik continued, _you won’t be my TA after this so I suppose we could do things like that on campus, it might cause a bit of a stir but that might be even more fun than having you as my dirty little secret._

_I’m not your dirty little secret, Erik._

_God, you really are. I mean, if those students knew what I’d done to you whilst you were grading those—_ Charles tried not to remember but Erik was remembering for him.

 _Stop it, seriously, we_ can’t. _I have three more students to see._

As if on cue, Charles spotted the girl who’d been running late coming through the door and he tried not to think about his half-hard cock and what he’d been doing when he’d written the comments he was now going to have to read back to her.

He got through the last three meetings - though he wasn’t entirely sure how. He had to tell the girl who’d been late that he could only see her, strictly, until her timeslot was up or, at best, until the next person showed up for theirs if they were late, too. “I have a, um, very important appointment to keep,” he tried to explain without thinking of exactly what he intended to do when he was finally done with the meetings.

After handing back work to the final student, he headed straight for Erik’s car. “Get in the back seat,” Erik said, as Charles approached, and Charles would have asked why but Erik continued, “we have some business to deal with before we leave.”

As Erik climbed in after him and pressed down on top of him, Charles said: “What if someone sees?”

“You won’t let them see, or, if you do, you’ll make them forget,” he was nuzzling at Charles’ neck, his hands unbuttoning Charles’ trousers, “I know you can do that. Unless, I mean,” Erik said, withdrawing his hands and raising his eyes to Charles’ “you don’t want to?”

_God, Erik, yes. If you stop I’ll—_

“That’s more like it,” Charles could feel Erik’s teeth on his neck, his fingers on the skin of his abdomen as he tugged at the waistband of his jeans.

 

A few hours later, they were a hundred miles outside of the city and Erik kept glancing over at Charles until Charles had to ask why.

“I just can’t stop thinking how I never counted on this - on you. When I requested you as my TA it was because I was curious about your research but I never thought I’d get this much. When you first came to my office I knew I’d got more than I’d bargained for but, Charles, what we have is—”

“Indescribable, I know, I feel the same way.” Charles said, looking out at the road ahead of him. He wasn’t sure whether Erik was really talking about their relationship or his discovery of other mutants but it didn’t matter, the two were curiously entwined somehow and the hope Charles felt for the future, as he looked out at the darkening sky, was contingent on both. He and Erik were going to do this together and that was important but what they were doing was important, too. As long as they were together, Charles thought, feeling half-foolish even as he thought it, nothing could go wrong.


End file.
